This invention relates to electric motor structure and more particularly to an improved drain structure for a vertically mounted electric motor to be positioned below a liquid sump into which the rotor shaft of the motor can be connected.
It is generally well known to mount an electric motor below a liquid sump to connect the motor to a sump pump or the like, such as in dishwasher applications. Liquid leakage may sometimes occur along the seal between the sump pump and the rotor shaft, the leakage, if not noticed and stopped, exposing the several parts of the motor to what could prove to be serious damage.
Various types of arrangements have been utilized to direct liquid leakage from the sump away from the electric motor, including splash guards mounted on the rotor shaft between the seal and the endshield and more recently the structural arrangement, as disclosed in U.S. Pat. No. 4,535,262, has been utilized wherein the endshield itself is contoured to direct liquid to drain holes in the endshield for discharge of the liquid at a location removed from the motor parts. These past arrangements, for the most part, have been comparatively complex and expensive in manufacture and assembly and particularly have failed to be effective in situations where the upper surface of the endshield has been utilized to gather and drain liquids with an external rotating part thereabove, the rotating part often throwing or misting the liquid on the upper surface of the endshield so that it might coat exposed parts adjacent the motor as well as in the motor.
The present invention, recognizing the problems of the various structures of the past, including those of the more recent past, provides an improved drain structure for an electric motor which is comparatively straightforward and inexpensive in manufacture and assembly and yet assures proper removal and drainage of any liquid leakage from a sump above the motor, even though the upper endshield of such motor structure might further include an external rotating part thereabove. In addition, the present invention recognizes and resolves problems associated with formation of liquid menisci, as well as the undesirability of uncontrolled liquid sprays and mist, particularly in instances where rotating parts external of the motor and below the sump are utilized, the present invention providing a unique structural arrangement to avoid any such structural problems.
Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth herein.